"Wartime in Washington," tonight at 10 on Channel 26, probes the leading edge of documentary television. It is an intelligent, provocative, at times even sexy show about the city's transformation from the cliche' "sleepy southern town" to a boom-town world capital.

The camera never blinks as the raw hub city is suddenly infused during World War II with hundreds of thousands of people anxious about their future and that of the nation.

But the program goes beyond the city's problems of handling that sudden burst of population, and such architectural convulsions as temporary housing thrown up on the Mall or a Pentagon built in the suburbs.

It focuses rightly on the sudden shifts in the lives of the people who lived here; the eroding of class distinctions and racial divisions, and the explosion of opportunities for women. All these cultural shocks emerge in this first-rate program as Washington mushrooms for the first time into a true metropolis.

This is fascinating stuff, especially to Washingtonians with little sense of this turning point in the city's history 40 years ago. The program's major shortcoming is that it leaves viewers hungry for more.

To see sailors and soldiers dancing at the USO off Lafayette Square and hear of new sexual attitudes among "government girls" and men in uniform suddenly away from home in the crisis atmosphere of a capital at war is to want a fictional version of that same story.

To see black domestics suddenly thrust into government jobs and onto the police force is to sense the heat of radical human change that came to a small town on the Potomac because of the war. We want to see more and feel more of the sudden shifts in individual lives.

These sparks of heat and soul are budding flowers in the show. The images from those prevideo days are limited to newsreel film rather than more personal, up-close visions of individuals. Yet they fire the imagination with thoughts of wartime love affairs; of human aspiration; of women seizing opportunities to move up in careers previously unavailable to them; of blacks suddenly emerging as government workers; of the old Washington etiquette crumbling under the siege of young people rushing into the city to save their country.

This is one public broadcasting effort that could be a pilot for a hot commercial TV mini-series, and it achieves that passion and level of interest with no loss of intelligence.

The show does not follow Washington and its social changes beyond the war years, nor does it deal with the question of how many of those changes would wait another 20 years to come to full fruition. But to a Washingtonian, even the old, gray film of the city is exciting.

There is the Mount Pleasant bus -- circa 1943.

There is a dusty port of Georgetown, complete with trolley cars.

There are the Redskins, playing a game as war is declared in the aftermath of Pearl Harbor.

There are Jimmy Cagney, Lucille Ball and Fred Astaire driving down an ancient Pennsylvania Avenue in support of war bonds.

This is documentary TV at its best and most exciting: bringing history alive and giving it meaning.

The program slows somewhat in current interviews with people who lived through those times, for their faces are always less exciting than their comments, and merely accentuate the inability of old movie reels to take us beneath the surface of individual lives.

But that shortcoming appears more a limitation of art form than effort in this show, which remains an exemplary documentary.